Modern Front-End Development for Rails

Using TypeScript

We’ve already installed TypeScript back in Chapter 1, ​Getting Started with Client-Side Rails​ by adding the Babel preset-typescript plugin and the webpack fork-ts-checker-webpack-plugin. TypeScript’s configuration is managed by a tsconfig.json file, which basically specifies what TypeScript allows and the kind of code that TypeScript emits. (We’ll talk about more about the tsconfig.json file in Chapter 14, ​Validating Code with Advanced TypeScript​.)

We don’t have to explicitly call the TypeScript compiler. With TypeScript in place, whenever webpack processes our code, it will include the TypeScript compilation step. The TypeScript compiler will run, and if all its type checking passes, it will output JavaScript that webpack ...